Positioning mechanism for a wooden article engaging device

ABSTRACT

A positioning mechanism for a wooden article engaging device having a frame, a rocker arm, first and second air cushions and an eccentric member is provided. The rocker arm has a first end pivotally connected to the frame and a second end connected to the device. The first and second air cushions are fixed between the frame and the rocker arm. Each of the first and second air cushions has an air pressure therein which is controllable to vertically pivot the rocker arm in order to position the wooden article engaging device in one of a clearance position and a working position. The eccentric member eccentrically pivots about a generally horizontal axis, the at least one eccentric member is engages the rocker arm when in the working position. In this way, the eccentric pivoting of the eccentric member acts to pivot the rocker arm to further adjust the device.

FIELD OF THE INVENTION

The present invention relates to wood processing machinery. Moreparticularly, the present invention concerns a positioning mechanism fora wooden article engaging device such as a roller or the like.

BACKGROUND OF THE INVENTION

In the wood processing industry, wooden articles of varying sizes andshapes, and in varying stages of processing and finishing, aretransported to and from wood processing machines, along conveyors andthe like, in controlled production lines. Such a wooden article istransported along a specific path and must approach each successiveprocessing station at a specific speed and in a specific orientation.

If a plank is improperly guided during transportation, the risk of itbeing misaligned as it is received by a processing machine is greatlyincreased. During processing, such a misalignment can lower the accuracyand effectiveness of the processing machine, for example a planer, acontouring machine, a molder or the like, increase the failure rate andresult in a wasting of the material. Moreover, modern conveyorstransport planks at high speeds and misalignment at any stage of theproduction line could cause damaging collisions, jams and equipmentbreakdowns, resulting in lost production and costly delays.

It is known in the art to provide a wooden article engaging device, forexample rollers, rails, belt conveyors or the like for implementationalone, or in combination, with processing equipment in order to engagethe wooden articles. Such devices guide the moving planks before, duringor after the processing operation so as to ensure their proper alignmentwith the processing machines.

Rollers, for example, rotate at a desired speed, driving the plank alongthe line. In addition they may also be operable to apply a pressure tothe planks in order to keep them on the track. In order to control thepressure applied and accommodate planks of varying dimension, thedistance between the roller and the track is variable.

In order to compensate for any unevenness in the plank, it is known tomount the rollers or the like with resilient shock absorbing mechanisms,such as an air cushion or other resilient member, in order to keep theapplied pressure constant. U.S. Pat. No. 6,283,353 (GILBERT) teaches aroller device for applying pressure on a wooden article including an aircushion disposed between the roller and the frame above the armsupporting the roller.

A major drawback associated with positioning mechanisms, is that theyare difficult to adjust. More specifically, operation of such prior artdevices must generally be stopped in order to perform any adjustment ofthe position of the device.

In view of the above, there is remains a need for an improvedpositioning mechanism for wooden article engaging devices with increasedadjustability and ease of operation.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a positioningadjustment mechanism for a wooden article engaging device which, byvirtue of its design and components, satisfies some of theabove-mentioned needs and is thus an improvement over other relatedassemblies known in the prior art.

In accordance with the present invention, the above object is achieved,as will be easily understood, with a positioning mechanism such as theone briefly described herein and such as the one exemplified in theaccompanying drawings.

In accordance with a first aspect of the present invention, there istherefore provided a positioning mechanism for a wooden article engagingdevice having a frame, a rocker arm, first and second air cushions andat least one eccentric member. The rocker arm has a first end pivotallyconnected to the frame and a second end connected to the wooden articleengaging device. The first and second air cushions are fixed between theframe and the rocker arm, on either side of the rocker arm. Each of thefirst and second air cushions has an air pressure therein which iscontrollable to vertically pivot the rocker arm in order to position thewooden article engaging device in one of a clearance position and aworking position. The at least one eccentric member eccentrically pivotsabout a generally horizontal axis with respect to the frame, and isoperable to engage the rocker arm when the wooden article engagingdevice is in the working position. In this way, the eccentric pivotingof the at least one eccentric member with respect to the axis acts topivot the rocker arm to further adjust the wooden article engagingdevice within the working position.

In accordance with a second aspect of the present invention, there isalso provided a positioning system for a plurality of wooden articleengaging devices. The positioning system includes a plurality ofpositioning mechanisms each associated with a corresponding woodenarticle engaging device. Each positioning mechanism has a rocker arm,first and second air cushions and at least one eccentric member. Therocker arm has a first end pivotally connected to the frame and a secondend connected to the corresponding wooden article engaging device. Thefirst and second air cushions are fixed between the frame and the rockerarm, on either side of the rocker arm. Each of the first and second aircushions has an air pressure therein which is controllable to verticallypivot the rocker arm in order to position the wooden article engagingdevice in one of a clearance position and a working position. The atleast one eccentric member eccentrically pivots about a generallyhorizontal axis with respect to the frame. The at least one eccentricmember is operable to engage the rocker arm when the wooden articleengaging device is in the working position. In this way, the eccentricpivoting of the at least one eccentric member with respect to the axisacts to pivot the rocker arm to further adjust the wooden articleengaging device within the working position. The positioning systemfurther includes at least one synchronization member operativelyconnected between the eccentric members of adjacent mechanisms forsynchronizing the adjustment of the plurality of wooden article engagingdevices.

Advantageously, this present invention provides a positioning mechanismand system for a wooden article with increased adjustability and ease ofoperation.

The invention and its advantages will be better understood by readingthe following non-restrictive description of a preferred embodimentthereof, made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will becomeapparent upon reading the detailed description and upon referring to thedrawings in which:

FIG. 1 is a partial cutaway perspective view of a positioning mechanismin accordance with an embodiment of the present invention.

FIG. 2 is a rear view of the positioning mechanism of FIG. 1.

FIG. 3 is a side view of the positioning mechanism of the previousFigures in a working position, showing an adjusted working position inphantom lines, the rocker arm being shown in transparency.

FIG. 4 is a cross-sectional view taken along IV-IV in FIG. 2 of thepositioning mechanism in a clearance position.

FIG. 5 is a cross-sectional view taken along IV-IV in FIG. 2 of thepositioning mechanism in a working position.

FIG. 6 is a perspective view of a positioning system in accordance withanother embodiment of the present invention.

FIG. 7 is a partial perspective view of the positioning system of FIG.6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, the same numerical references refer tosimilar elements. The embodiments shown in the figures are preferred,for exemplification purposes only.

In the context of the present description, the expression “woodenarticle” includes all appropriate types of wood products, as apparent toa person skilled in the art. For this reason, the expressions “timber”,“lumber”, “board”, “plank” or “article ”, for example, should not betaken as to limit the scope of the present invention, may be usedinterchangeably and include all other kinds of items with which thepresent invention may be used and could be useful.

In addition, although the preferred embodiments of the present inventionas illustrated in the accompanying drawings include various components,etc., and although the preferred embodiments of the positioningmechanism and system and corresponding parts of the present invention asshown consist of certain geometrical configurations as explained andillustrated herein, not all of these components and geometries areessential to the invention and thus should not be taken in theirrestrictive sense, i.e. should not be taken as to limit the scope of thepresent invention. It is to be understood, as also apparent to a personskilled in the art, that other suitable components and co-operationstherebetween, as well as other suitable geometrical configurations maybe used for the positioning mechanism and system according to thepresent invention, as will be briefly explained herein and as can beeasily inferred herefrom by a person skilled in the art, withoutdeparting from the scope of the invention.

With reference to FIGS. 1 to 5, there is shown a positioning mechanism10 for a wooden article engaging device 16 according to a firstembodiment of the present invention. The positioning mechanism 10includes a frame 12 mounted in proximity to the path of a wooden article(not shown), and a rocker arm 14 pivotally mounted to the frame 12 forholding the wooden article engaging device 16. In the presentembodiment, the wooden article engaging device 16 is preferably aroller, although, other suitable devices, such as belt conveyors or thelike, are also within the scope of the present invention.

In the illustrated embodiment, the rocker arm 14 is pivotally connectedto the frame 12 about an axle 18, enabling the roller 16 to be pivotedbetween an upper “clearance position” where the roller 16 is elevatedand away from the path of the wooden article, and a lower “workingposition”, where the roller 16 is lowered and apt to interact with thewooden article. These positions are best seen in FIGS. 4 and 5,respectively. A first air cushion 20 and a second air cushion 22 aredisposed on opposite sides of the rocker arm 14 to effect this pivoting.Control of the air pressure in both these air cushions enables andoperator to position the roller 16 in either of the clearance andworking positions, as will be discussed in further detail herein below.

The frame 12 is preferably provided with a base 24 for fixing themechanism 10 along a processing line, and left and right side walls 26and 28 extending substantially vertically from the base 20 andsubstantially parallel to one another. Extending transversally betweenthe side walls 26 and 28 are upper and lower cushion supports 30 and 32for retaining the upper and lower air cushions 20 and 22, respectively.

Referring more particularly to FIG. 1 showing the positioning mechanism10 in a partial cutaway, the rocker arm 14 preferably includes left andright side panels 34 and 36, also extending substantially vertically inparallel to one another. Extending between the side panels 34 and 36 isa cushion seat 38 having upper and lower faces 40 and 42. The upper andlower faces 40 and 42 serve to connect the upper and lower air cushions20 and 22 to the rocker arm 14, respectively. Preferably, the aircushions 20 and 22, the cushion supports 30 and 32 of the frame 12, andthe faces 40 and 42 are all at least partially angled about the axle 18.As seen best in the cross-sectional views of FIGS. 4 and 5, the planesof the cushion supports 30 and 32 are aligned radially with the axis ofthe axle 18. The upper face 40 is disposed so as to be substantiallyparallel to the upper cushion support 30 when the mechanism 10 is in theclearance position (see FIG. 4). In addition, the cushion seat 38, inthe area of the upper and lower faces 40 and 42, is triangular.Consequently, when the lower air cushion 22 is inflated, the upper aircushion 20 may advantageously be reduced to its smallest volume.Similarly, the lower face 42 is disposed to as to be substantiallyparallel to the lower cushion support 32 when the mechanism 10 is in theworking position (see FIG. 5).

Advantageously, in the present embodiment the left and right side panels34 and 36 are disposed outside of the side walls 26 and 28. It will benoted that the cushion supports 30 and 32, faces 40 and 42 and sidewalls 26 and 28 preferably surround the air cushions 20 and 22 in orderto protect them from damage.

In operation, the roller 16 is driven by a motor (not shown) operativelyconnected to the free end of the axle 18 extending from the left sidepanel 34. The motion of the axle 18 is transferred to the roller 16,which rotates about a roller axle 46, via gearing 44. The gearing 44 ismounted directly to the right side panel 36. The axle 46 passes throughthe cushion seat 38 and is mounted, preferably via roller bearings, atboth the left and right side panels 34 and 36. The motor axle 46 ispreferably substantially parallel to the axle 18.

Positioned on opposite sides of the rocker arm 14, the upper and lowerair cushions 20 and 22 cooperate to position the roller 16 by acoordinated inflation of one and deflation of the other. In the firstembodiment, this opposition of positions is achieved by positioning thefirst and second air cushions 20 and 22 above and below the rocker arm14, respectively.

When the lower air cushion 22 is inflated, as seen in FIG. 4, the roller16 is lifted and said to be in the clearance position. This position isuseful for inspecting the roller, for clearing jams, for removing piecesat the end of a production cycle, and the like.

When the upper air cushion 20 is inflated and the lower air cushion 22is deflated, as seen in FIGS. 1 and 5, the roller 16 is allowed to dropand said to be in the working position and operable to engage lumberpassing therebelow. By regulating the degree of inflation of each aircushion 20 and 22, and more specifically the air pressure within theupper air cushion 20, the upper air cushion 20 is operable to absorb theshocks resulting from the engagement of the roller 16 with the planks.The air pressure in the air cushions 20 and 22 is preferably controlledvia an air pump (not shown) via pneumatic tubing (also not shown).

As will be apparent to one of ordinary skill in the art, the expressions“inflated” and “deflated” as used herein are not to be construed inabsolute terms indicating a complete filling or emptying of air within agiven cushion. Rather, the air pressure in the upper air cushion 20 maybe simply released as the lower air cushion 22 is expanded, and viceversa.

In an alternate embodiment, the rocker arm 14 extends on both sides ofthe axle 18 and the first and second air cushions 20 and 22 are disposedbehind and in front of the axle 18. As will be apparent to one ofordinary skill in the art, placing the air cushions 20 and 22 onopposite sides of the axis of rotation, both either above or below therocker arm 14, achieves exactly the same functionality as if the aircushions 20 and 22 were vertically opposite one another. More precisely,the inflation of the first air cushion 20 located behind the axle 18 andbelow the rocker arm 14, combined with the corresponding deflation ofthe second air cushion 22 located between the axle 18 and the roller 16will put the roller 16 in the working position. As will be furtherapparent to one of ordinary skill in the art, a similar arrangementwherein both air cushions are above the rocker arm 14 and on either sideof axle 18 is similarly within the scope of the present invention.

FIGS. 4 and 5, which show the mechanism 10 in cross-section, illustratethe maximum and minimum heights 46 and 48 of the roller 16,respectively. Given, for example, a 12 inch (30.48 centimeters) diameterroller, the maximum height 46 is 5¼ inches (13.34 centimeters). This isthe height of the roller 16 in the clearance position in one embodimentof the invention. In this example, the minimum height 48 is 15/16 inches(2.38 centimeters). This minimum height 48 is the lowest possibleworking position, however the working position is not limited to thisminimum position, as will be evident from the description below.

While in the working position, the height of the roller 16 is furtheradjustable by an eccentric member 50 which is eccentrically pivotableabout a generally horizontal axis with respect to the frame 12.Preferably, the mechanism 10 includes two such eccentric members 50projecting laterally outward from an adjustment shaft 52 disposedtherebetween and engaging the left and right side panels 34 and 36. Theadjustment shaft 52 passes through the frame 12 and is mounted,preferably via roller bearings, on both the left and right side panels34 and 36. Preferably, the adjustment shaft 52 is substantially parallelto the axle 18.

In a preferred embodiment, the eccentric member 50 has a circularcross-section of lesser diameter than that of the adjustment shaft 52.Because the member 50 is eccentric, i.e. the axis of the adjustmentshaft, about which it rotates, does not coincide with its geometriccenter, any rotation thereof will possess a translational component. Inthe working position, the eccentric member 50 engages the rocker arm 14and thereby displaces it upon its eccentric rotation with respect to theframe 12.

In an alternate embodiment, and equally within the scope of the presentinvention, the eccentric member 50 may be cam-shaped, that is having anon-circular cross section. In such a case, any rotation, whether aboutthe geometric centre of the member 50 or not, will similarly cause adisplacement of the rocker arm 14 when it is engaging its periphery.

With specific reference to FIG. 3, the rocker arm 14 and roller 16 areshown at the minimum height 48, as well as in phantom lines at a maximumworking height 54. Returning to the example of a 12 inch (30.48centimeters) roller 16, the maximum working height 54 is 3⅛ inches (7.94centimeters). This variation in working height corresponds to a rotation56 of the eccentric member 50, in this case a rotation of 70°.

As illustrated, the eccentric member 50 is located below the rocker arm14 such that the rocker arm 14 sits thereon, engaging its periphery.Preferably, the eccentric member engages the rocker arm 14 via a block58 having a flat surface 60. As the eccentric member 50 rotates withrespect to the frame 12, the block 58 can pivot about the eccentricmember 50 and maintain its contact with the rocker arm 14 along the flatsurface 60. Preferably, the block 58 is made of a firm but resilientmaterial, for example a rubber, which contributes to further dampen anyshock transmitted from the device 16 to the frame 12.

Once in the working position, the roller 16 can be further adjusted toany position between the minimum height 48 and the maximum workingheight 54 by rotating the adjustment shaft 52 and displacing theeccentric member 50.

With reference to FIGS. 6 and 7, there is shown a positioning system 90for a plurality of wooden article engaging devices 16, for example tworollers 16, according to a second embodiment of the present invention.The positioning system 90 as embodied herein includes two positioningmechanisms 100 each of which corresponding substantially to thepositioning mechanism as described hereinabove.

As in the previous embodiment, each positioning mechanism 100 includes aframe 112 mounted in proximity to the path of a wooden article and arocker arm 114 pivotally mounted thereto for holding a roller 116. Inthis particular embodiment, a second, non-adjustable roller 118 isprovided beneath each roller 116 for rotating in conjunction therewith.Again, each rocker arm 114 includes side panels 134 and 136, and acushion seat 138 extending therebetween, as well as a pair of eccentricmembers 150 projecting eccentrically from an adjustment shaft 152.

The positioning system 90 further includes a synchronization member 160operatively connected between the eccentric members 150 so as tosynchronize the adjustment of the plurality of rollers 116. Thesynchronization member 160 may be directly or indirectly connected, butis preferably a mechanical link pivotally connected to each adjustmentshaft 152, although it may also be, but is in no way limited to, apneumatic or hydraulic circuit, an electronic position encoder withservomotors and a controller, or a rack engaging a pinion attached toeach eccentric member 150.

In order rotate the adjustment shaft 152, a linear actuator 162 isoperatively connected thereto by a linking member 164. The linearactuator 162 can be an electrically or electronically controlled servomotor, but is preferably a screw jack 162 operable by a handle 166 andlockable by a lock 168. In use, an operator adjusts the working heightof the device 116 in accordance with the thickness of a particular plankto be processed by turning the handle 166, which drives the screw jack162 and rotates the adjustment shaft 152 of a first mechanism 100. Theadjustment of the working height of the first mechanism 100 istransferred to the remaining mechanisms 100 of system 90 bysynchronization member 160. The lock 168 is provided to ensure that theworking position is not further altered during operation.Advantageously, this adjustment can be safely and easily carried outduring operation of the rollers 116 and hence without unduly disruptingthe production line.

As will be apparent to one of ordinary skill in the art, the use of theactuator 162, the handle 166, and the lock 168 is not limited to thesystem 90 but is equally applicable to the system 10 of FIGS. 1 to 5.

As being now better appreciated, the present invention is an improvementand presents several advantages over other related devices and/ormethods known in the prior art. Indeed, the present invention isparticularly advantageous in that it provides a positioning system for awooden article engaging device with increased adjustability and ease ofoperation.

Of course, numerous modifications could be made to the above-describedembodiments without departing from the scope of the invention, asapparent to a person skilled in the art. While a specific embodiment ofthe present invention has been described and illustrated, it will beapparent to those skilled in the art that numerous modifications andvariations can be made without departing from the scope of the inventionas defined in the appended claims.

1. A positioning mechanism for a wooden article engaging device, thepositioning mechanism comprising: a frame; a rocker arm having a firstend pivotally connected to the frame and a second end connected to thewooden article engaging device; first and second air cushions fixedbetween the frame and the rocker arm on opposite sides of the rockerarm, each of the first and second air cushions having an air pressuretherein controllable to vertically pivot the rocker arm so as toposition the wooden article engaging device in one of a clearanceposition and a working position; at least one eccentric membereccentrically pivotable about a generally horizontal axis with respectto the frame, the at least one eccentric member being operable to engagethe rocker arm when the wooden article engaging device is in the workingposition so that eccentric pivoting of the at least one eccentric memberwith respect to the axis pivots the rocker arm to further adjust thewooden article engaging device within the working position.
 2. Thepositioning mechanism of claim 1, further comprising an adjustment shaftrotationally connected to the frame and rotatable about the axis, the atleast one eccentric member projecting eccentrically therefrom.
 3. Thepositioning mechanism of claim 2, further comprising a linear actuatorfor rotating the adjustment shaft.
 4. The positioning mechanism of claim2, further comprising a linking member operatively disposed between theadjustment shaft and the linear actuator.
 5. The positioning mechanismof claim 3, further comprising a radial arm extending radially from theadjustment shaft, the linking member being operatively connected to aradial arm.
 6. The positioning mechanism of claim 3, wherein the linearactuator is actuated by a handle.
 7. The positioning mechanism of claim6, wherein the handle is lockable.
 8. The positioning mechanism of claim1, further comprising a block operable to pivot about the at least oneeccentric member, the block having a flat surface for contacting therocker arm along a corresponding surface.
 9. The positioning mechanismof claim 8, wherein the block is made of rubber.
 10. The positioningmechanism of claim 1, wherein the frame comprises left and right sidewalls, the first and second air cushions being located laterallytherebetween.
 11. The positioning mechanism of claim 10, wherein thefirst air cushion is fixed above the rocker arm and the second aircushion is fixed below the rocker arm.
 12. The positioning mechanism ofclaim 11, wherein the frame further comprises upper and lower cushionsupports extending between the left and right side walls, the upper andlower cushion supports retaining the first and second air cushions,respectively.
 13. The positioning mechanism of claim 12, wherein therocker arm comprises left and right side panels, said left and rightside panels being pivotally connected to the left and right side walls,respectively.
 14. The positioning mechanism of claim 13, wherein therocker arm further comprises a cushion seat extending between the leftand right side panels and having upper and lower faces, the upper andlower faces engaging the first and second air cushions, respectively.15. The positioning mechanism of claim 14, wherein the cushion seat hasan at least partially triangular cross-section.
 16. The positioningmechanism of claim 15, wherein the at least one eccentric membercomprises a pair of eccentric members each operable to engage arespective one of the left and right side panels.
 17. The positioningmechanism of claim 16, further comprising an adjustment shaft pivotallyconnected to the frame and pivotable about the axis, the eccentricmembers projecting eccentrically from opposing ends thereof.
 18. Thepositioning mechanism of claim 1, wherein the first air cushion airpressure is regulated to dampen movement of the rocker arm when thewooden article engaging device is in the working position.
 19. Apositioning system for a plurality of wooden article engaging devices,the positioning system comprising: a plurality of positioningmechanisms, each positioning mechanism associated with a correspondingone of the plurality of wooden article engaging devices, eachpositioning mechanism comprising: a frame; a rocker arm having a firstend pivotally connected to the frame and a second end connected to thecorresponding wooden article engaging device; fist and second aircushions fixed between the frame and the rocker arm on opposite sides ofthe rocker arm, each of the first and second air cushions having an airpressure therein controllable to vertically pivot the rocker arm so asto position the corresponding wooden article engaging device in one of aclearance position and a working position; and at least one eccentricmember eccentrically pivotable about an axis with respect to the frame,the at least one eccentric member operable to engage the rocker arm whenthe corresponding wooden article engaging device is in the workingposition so that eccentric pivoting of the at least one eccentric memberwith respect to the axis pivots the rocker arm to further adjust thecorresponding wooden article engaging device within the workingposition; and at least one synchronization member operatively connectedbetween the eccentric members of adjacent mechanisms for synchronizingthe adjustment of the plurality of wooden article engaging devices.